ZONE OF ELUVIATION

The two uppermost zones in the soil profile, consisting of the A-Horizon, from which soluble Salts and Colloids are leached, and in which organic matter has accumulated and generally constitutes the most fertile soil layer, and the B-Horizon, or the lower soil zone which is enriched by the deposition or precipitation of material from the overlying zone, or A-horizon. Also referred to as the Solum.